Two members of Congress left some information in the dark when filling out their personal financial disclosure forms, which were made public last week.

According to ethics rules, if a member of Congress sits on the board of directors at a nonprofit, he or she is supposed to disclose the position. But at least two representatives—Corrine Brown, D-Fla., and Ander Crenshaw, R-Fla.—have failed to do so. The lawmakers' positions were discovered while researching lobbying reports, where lobbyists report honorary gifts to charities tied to members of Congress. There could be many more members of Congress making the same mistake.

One of the members—Rep.Crenshaw—was not aware of his position on the board. He presumed he was only an honorary board member, which does not mandate disclosure, his spokeswoman Barbara Riley said. Meanwhile, Rep. Brown did not disclose her role because she's never gone to a meeting and rarely joins boards because of her busy schedule, her chief of staff Ronnie Simmons said.

The two members' participation with these nonprofits is minimal or nonexistent, staffers said, which raises the question of why the organizations call them board members year after year, both on tax forms and on their websites. Both Brown and Crenshaw will file amended reports to reflect their board memberships, aides said.

After Crenshaw's non-disclosure was brought to his attention by the Reporting Group, he said he believed he was merely an honorary board member of the Big Brothers Big Sisters of Northeast Jacksonville. Brown, a board member of Communities in Schools of Jacksonville, a nonprofit that operates after-school programs and whose donors include the foundations of Bank of America and JPMorgan Chase, said the non-disclosure was an oversight.

“Neither of us was here on the day they were turned in to go over it with a fine-toothed comb,” Simmons said and confessed that he did not know his boss is a board member.

The lawmakers' oversights are evident on the first page of the personal financial disclosures, where they are asked, “Did you hold any reportable positions on or before the date of filing in the current calendar year?” Both Brown and Crenshaw checked the box ‘No.’

Crenshaw, a longtime congressman is sending a letter to the House Ethics Committee today which states that he will amend his reports going back to 2008, when he joined he board and that, going forward, he has decided to be an honorary member, Riley said. The nonprofit in question also receives donations from the charitable foundations of Bank of America and JPMorgan Chase.

A third member of Congress, Rep. Cathy McMorris Rodgers, R-Wash., may have also skirted the ethics rules. The vice chair of the Republican caucus is a board member of Spokane Neighborhood Action Partners but long ago appointed an alternate—a former district director—to serve on the board in her place, spokesman Todd Weiner said. After being contacted by the Reporting Group, her staff asked the House Ethics Committee if disclosing the position is necessary and is waiting for an answer, Weiner added. SNAP receives some of its donations from the likes of Wells Fargo, Microsoft and JPMorgan Chase. The nonprofit provides services such as foreclosure prevention to low-income families.

Not all members of Congress neglected to share their ties to nonprofits in the personal financial reports. Congressman Jim Himes, D-Conn., noted that he is one of the directors of the Fairfield County Community Foundation, which calls itself the “region’s center of philanthropy” on its website.